Break out the birthday cake and line up the candles: next year marks 35 years since the invention of business class air travel.

Or perhaps it's 34 years, depending on how granular you want to get.

Many airlines are reducing their first class offering, mainly because business class is beyond what first class used to be.

While Qantas is considered to have coined the "business class" name in 1979, British Airways debuted the concept of a premium cabin between economy and first in 1978 with Club Class.

In the decades that followed, business class has become the golden goose for full-service airlines, even replacing first class throughout much of the fleet.

Qantas now offers its latest first class only on the Red Roo's flagship Airbus A380s, having replaced the primo pointy end on most Boeing 747s with the second-gen Skybed II business class seats.

Is business the new first class?

Boeing is also seeing most airlines ordering its new 787 Dreamliner with business class rather than first class nestled into the nose.

"We're seeing many airlines starting to reduce their full-blown first class offering, mainly because business class is beyond what first class used to be," Tom Galantowicz, Boeing's Director of 787 Interiors, told High Flyer last year.

"The front end of the 787 cabin has first class features, and business class is where the better airlines spend money because passengers are willing to pay for it."

So while the evolution, or some might say devolution of economy has been driven by reducing the cost of travel, business class continued to improve as a way of justifying its higher ticket price.

It's also become a hotly-contested area of competition between airlines looking to woo the business traveller – alongside in-flight service and airport lounges, of course.

Lie-flat beds that recline into a fully horizontal position are the new norm, partnered with a degree of privacy plus high-tech touches such as USB ports and ever-larger video screens.

And despite how much money they invest in business class seats, airlines know they can't afford to stand still.

Beyond the lie-flat bed ...

Cathay Pacific has what's considered to be one of the world's best business class seats, which is a dramatic turnaround from its previous generation of long, narrow and high-walled cubicles that some travellers dubbed "coffin class".

But the airline is already looking at an upgrade in 2016, when the first of its Airbus A350s arrive.

"There is a risk over the next few years that competitors that (today) have slightly sloped seats are going to catch up, and flatbeds and a 15" screen becomes the minimum expectation," says Toby Smith, Cathay's general manager for product.

Cathay shares a challenge faced by many of its competitors. "What do you do next?" Smith questions. "I mean, you can't get flatter than flat!

"You might make (the seat) a little bit wider or a little bit longer but if you've got a bed that takes someone who's 6' 2", 6' 3", that's probably going to be good enough."

Improved layouts on the way

How these seats are laid out in the cabin is also undergoing a change of direction – quite literally so.

Qantas currently retains the most traditional business class layout. Its Marc Newson-designed Skybed pods are arrayed in a straight line across the cabin, which means window passengers need to step gingerly over their slumbering seatmate to visit the loo, lounge or snack bar.

Downstairs in the 747s, there's also the dreaded middle seat in a 2-3-2 configuration.

The latest trends favour layouts which provides direct aisle access for every passenger.

These include herringbone-style seats which are angled towards or away from the windows, and staggered layouts where alternating seats dovetail into the one in front.

Business travellers can expect to see more of these as new types of aircraft are rolled out, including the Boeing 787 and Airbus A350, along with new members of the A380 club such as Thai Airways.

As we gather around the business class birthday cake, what's your current favourite business class seat? And what changes would you like to see in the next generation of business class?